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// run
// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Checks that conversion of CMP(x,-y) -> CMN(x,y) is only applied in correct context.
package main
type decimal struct {
d [8]byte // digits, big-endian representation
dp int // decimal point
}
var powtab = []int{1, 3, 6, 9, 13, 16, 19, 23, 26}
//go:noinline
func foo(d *decimal) int {
exp := int(d.d[1])
if d.dp < 0 || d.dp == 0 && d.d[0] < '5' {
var n int
if -d.dp >= len(powtab) {
n = 27
} else {
n = powtab[-d.dp] // incorrect CMP -> CMN substitution causes indexing panic.
}
exp += n
}
return exp
}
func main() {
var d decimal
d.d[0] = '1'
if foo(&d) != 1 {
println("FAILURE (though not the one this test was written to catch)")
}
}
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